On Sat, 2023-10-21 at 22:03 -0700, thinker.li@xxxxxxxxx wrote:
> From: Kui-Feng Lee <thinker.li@xxxxxxxxx>
>
> Create a new struct_ops type called bpf_testmod_ops within the bpf_testmod
> module. When a struct_ops object is registered, the bpf_testmod module will
> invoke test_2 from the module.
>
> Signed-off-by: Kui-Feng Lee <thinker.li@xxxxxxxxx>
Hello,
Sorry for the late response, was moving through the patch-set very slowly.
Please note that CI currently fails for this series [0], reported error is:
testing_helpers.c:13:10: fatal error: 'rcu_tasks_trace_gp.skel.h' file not found
13 | #include "rcu_tasks_trace_gp.skel.h"
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
I get the same error when try to run tests locally (after full clean).
On the other hand it looks like `kern_sync_rcu_tasks_trace` changes
are not really necessary, when I undo these changes but keep changes in:
- .../selftests/bpf/bpf_testmod/bpf_testmod.c
- .../selftests/bpf/bpf_testmod/bpf_testmod.h
- .../bpf/prog_tests/test_struct_ops_module.c
- .../selftests/bpf/progs/struct_ops_module.c
struct_ops_module/regular_load test still passes.
Regarding assertion:
> + ASSERT_EQ(skel->bss->test_2_result, 7, "test_2_result");
Could you please leave a comment explaining why the value is 7?
I don't understand what invokes 'test_2' but changing it to 8
forces test to fail, so something does call 'test_2' :)
Also, when running test_maps I get the following error:
libbpf: bpf_map_create_opts has non-zero extra bytes
map_create_opts(317):FAIL:bpf_map_create() error:Invalid argument (name=hash_of_maps)
[0] https://patchwork.kernel.org/project/netdevbpf/patch/20231022050335.2579051-11-thinker.li@xxxxxxxxx/
(look for 'Logs for x86_64-gcc / build / build for x86_64 with gcc ')
> ---
> tools/testing/selftests/bpf/Makefile | 2 +
> .../selftests/bpf/bpf_testmod/bpf_testmod.c | 59 +++++++++++++++++++
> .../selftests/bpf/bpf_testmod/bpf_testmod.h | 5 ++
> .../bpf/prog_tests/test_struct_ops_module.c | 38 ++++++++++++
> .../selftests/bpf/progs/struct_ops_module.c | 30 ++++++++++
> tools/testing/selftests/bpf/testing_helpers.c | 35 +++++++++++
> 6 files changed, 169 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c
> create mode 100644 tools/testing/selftests/bpf/progs/struct_ops_module.c
>
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index caede9b574cb..dd7ff14e1fdf 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -706,6 +706,8 @@ $(OUTPUT)/uprobe_multi: uprobe_multi.c
> $(call msg,BINARY,,$@)
> $(Q)$(CC) $(CFLAGS) $(LDFLAGS) $^ $(LDLIBS) -o $@
>
> +$(OUTPUT)/testing_helpers.o: $(OUTPUT)/rcu_tasks_trace_gp.skel.h
> +
> EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) $(SCRATCH_DIR) $(HOST_SCRATCH_DIR) \
> prog_tests/tests.h map_tests/tests.h verifier/tests.h \
> feature bpftool \
> diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
> index cefc5dd72573..f1a20669d884 100644
> --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
> +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
> @@ -1,5 +1,6 @@
> // SPDX-License-Identifier: GPL-2.0
> /* Copyright (c) 2020 Facebook */
> +#include <linux/bpf.h>
> #include <linux/btf.h>
> #include <linux/btf_ids.h>
> #include <linux/error-injection.h>
> @@ -517,11 +518,66 @@ BTF_ID_FLAGS(func, bpf_kfunc_call_test_static_unused_arg)
> BTF_ID_FLAGS(func, bpf_kfunc_call_test_offset)
> BTF_SET8_END(bpf_testmod_check_kfunc_ids)
>
> +#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
> +
> +DEFINE_STRUCT_OPS_VALUE_TYPE(bpf_testmod_ops);
> +
> +static int bpf_testmod_ops_init(struct btf *btf)
> +{
> + return 0;
> +}
> +
> +static bool bpf_testmod_ops_is_valid_access(int off, int size,
> + enum bpf_access_type type,
> + const struct bpf_prog *prog,
> + struct bpf_insn_access_aux *info)
> +{
> + return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
> +}
> +
> +static int bpf_testmod_ops_init_member(const struct btf_type *t,
> + const struct btf_member *member,
> + void *kdata, const void *udata)
> +{
> + return 0;
> +}
> +
> static const struct btf_kfunc_id_set bpf_testmod_kfunc_set = {
> .owner = THIS_MODULE,
> .set = &bpf_testmod_check_kfunc_ids,
> };
>
> +static const struct bpf_verifier_ops bpf_testmod_verifier_ops = {
> + .is_valid_access = bpf_testmod_ops_is_valid_access,
> +};
> +
> +static int bpf_dummy_reg(void *kdata)
> +{
> + struct bpf_testmod_ops *ops = kdata;
> + int r;
> +
> + BTF_STRUCT_OPS_TYPE_EMIT(bpf_testmod_ops);
> + r = ops->test_2(4, 3);
> +
> + return 0;
> +}
> +
> +static void bpf_dummy_unreg(void *kdata)
> +{
> +}
> +
> +struct bpf_struct_ops bpf_bpf_testmod_ops = {
> + .verifier_ops = &bpf_testmod_verifier_ops,
> + .init = bpf_testmod_ops_init,
> + .init_member = bpf_testmod_ops_init_member,
> + .reg = bpf_dummy_reg,
> + .unreg = bpf_dummy_unreg,
> + .name = "bpf_testmod_ops",
> + .owner = THIS_MODULE,
> +};
> +
> +#endif /* CONFIG_DEBUG_INFO_BTF_MODULES */
> +
> extern int bpf_fentry_test1(int a);
>
> static int bpf_testmod_init(void)
> @@ -532,6 +588,9 @@ static int bpf_testmod_init(void)
> ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &bpf_testmod_kfunc_set);
> ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &bpf_testmod_kfunc_set);
> ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL, &bpf_testmod_kfunc_set);
> +#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
> + ret = ret ?: register_bpf_struct_ops(&bpf_bpf_testmod_ops);
> +#endif
> if (ret < 0)
> return ret;
> if (bpf_fentry_test1(0) < 0)
> diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
> index f32793efe095..ca5435751c79 100644
> --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
> +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
> @@ -28,4 +28,9 @@ struct bpf_iter_testmod_seq {
> int cnt;
> };
>
> +struct bpf_testmod_ops {
> + int (*test_1)(void);
> + int (*test_2)(int a, int b);
> +};
> +
> #endif /* _BPF_TESTMOD_H */
> diff --git a/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c b/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c
> new file mode 100644
> index 000000000000..7261fc6c377a
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c
> @@ -0,0 +1,38 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
> +#include <test_progs.h>
> +#include <time.h>
> +
> +#include "rcu_tasks_trace_gp.skel.h"
> +#include "struct_ops_module.skel.h"
> +
> +static void test_regular_load(void)
> +{
> + struct struct_ops_module *skel;
> + struct bpf_link *link;
> + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts);
> + int err;
> +
> + skel = struct_ops_module__open_opts(&opts);
> + if (!ASSERT_OK_PTR(skel, "struct_ops_module_open"))
> + return;
> + err = struct_ops_module__load(skel);
> + if (!ASSERT_OK(err, "struct_ops_module_load"))
> + return;
> +
> + link = bpf_map__attach_struct_ops(skel->maps.testmod_1);
> + ASSERT_OK_PTR(link, "attach_test_mod_1");
> +
> + ASSERT_EQ(skel->bss->test_2_result, 7, "test_2_result");
> +
> + bpf_link__destroy(link);
> +
> + struct_ops_module__destroy(skel);
> +}
> +
> +void serial_test_struct_ops_module(void)
> +{
> + if (test__start_subtest("regular_load"))
> + test_regular_load();
> +}
> +
> diff --git a/tools/testing/selftests/bpf/progs/struct_ops_module.c b/tools/testing/selftests/bpf/progs/struct_ops_module.c
> new file mode 100644
> index 000000000000..cb305d04342f
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/struct_ops_module.c
> @@ -0,0 +1,30 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
> +#include <vmlinux.h>
> +#include <bpf/bpf_helpers.h>
> +#include <bpf/bpf_tracing.h>
> +#include "../bpf_testmod/bpf_testmod.h"
> +
> +char _license[] SEC("license") = "GPL";
> +
> +int test_2_result = 0;
> +
> +SEC("struct_ops/test_1")
> +int BPF_PROG(test_1)
> +{
> + return 0xdeadbeef;
> +}
> +
> +SEC("struct_ops/test_2")
> +int BPF_PROG(test_2, int a, int b)
> +{
> + test_2_result = a + b;
> + return a + b;
> +}
> +
> +SEC(".struct_ops.link")
> +struct bpf_testmod_ops testmod_1 = {
> + .test_1 = (void *)test_1,
> + .test_2 = (void *)test_2,
> +};
> +
> diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c
> index 8d994884c7b4..05870cd62458 100644
> --- a/tools/testing/selftests/bpf/testing_helpers.c
> +++ b/tools/testing/selftests/bpf/testing_helpers.c
> @@ -10,6 +10,7 @@
> #include "test_progs.h"
> #include "testing_helpers.h"
> #include <linux/membarrier.h>
> +#include "rcu_tasks_trace_gp.skel.h"
>
> int parse_num_list(const char *s, bool **num_set, int *num_set_len)
> {
> @@ -380,10 +381,44 @@ int load_bpf_testmod(bool verbose)
> return 0;
> }
>
> +/* This function will trigger call_rcu_tasks_trace() in the kernel */
> +static int kern_sync_rcu_tasks_trace(void)
> +{
> + struct rcu_tasks_trace_gp *rcu;
> + time_t start;
> + long gp_seq;
> + LIBBPF_OPTS(bpf_test_run_opts, opts);
> +
> + rcu = rcu_tasks_trace_gp__open_and_load();
> + if (IS_ERR(rcu))
> + return -EFAULT;
> + if (rcu_tasks_trace_gp__attach(rcu))
> + return -EFAULT;
> +
> + gp_seq = READ_ONCE(rcu->bss->gp_seq);
> +
> + if (bpf_prog_test_run_opts(bpf_program__fd(rcu->progs.do_call_rcu_tasks_trace),
> + &opts))
> + return -EFAULT;
> + if (opts.retval != 0)
> + return -EFAULT;
> +
> + start = time(NULL);
> + while ((start + 2) > time(NULL) &&
> + gp_seq == READ_ONCE(rcu->bss->gp_seq))
> + sched_yield();
> +
> + rcu_tasks_trace_gp__destroy(rcu);
> +
> + return 0;
> +}
> +
> /*
> * Trigger synchronize_rcu() in kernel.
> */
> int kern_sync_rcu(void)
> {
> + if (kern_sync_rcu_tasks_trace())
> + return -EFAULT;
> return syscall(__NR_membarrier, MEMBARRIER_CMD_SHARED, 0, 0);
> }
